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resources of the network depending upon the priorities assigned to them.
7. Connection establishment and termination. These rules define how connections
are established, maintained and terminated when two nodes of a network want to
communicate with each other.
8. Data security. Providing data security and privacy is also built into most
communication software packages. It prevents access of data by unauthorized
9. Log information.
Several data communication software are also designed
to develop log information, which consists of all jobs and data communications tasks that have taken place. Such information is normally used for charging the
various users of the network based on their usage of the network resources.
Concept of Layered Protocols in Network Design
Most modern computer networks are designed in a modular or structured fashion
for easy and efficient handling of the system. They are normally split up into a
series of modules and are logically composed of a succession of layers or levels.
Each layer offers certain services to the higher layers, shielding those layers from
the details of how the offered services are actually implemented. Each layer has its
own set of protocols. A particular layer of one machine communicates only with
the corresponding layer of another machine using the protocols of this layer.
The main reasons for using the concept of layered protocols in network design are
The protocols of a network are fairly complex. Designing them in layers
makes their implementation more manageable.
2. Layering of protocols provides well-defined interfaces between the layers, so
that a change in one layer does not affect an adjacent layer. That is, the various
functionalities can be partitioned and implemented independently so that each one
can be changed as technology improves without the other ones being affected. For
example, a change to a routing algorithm in a network control program should not
affect the functions of message sequencing, which is located in another layer...
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This document was uploaded on 04/07/2014.
- Spring '14